Development of trityl group-anchored solubilizing tags for peptide and protein synthesis

: Recently, solubilizing tag methods (Trt-K and Trt-R method) were developed for the challenging synthesis of peptides/proteins by means of native chemical ligation. In this system, the solubilizing tag can be attached to the Cys side chain by simply mixing the tag-introducing reagent under acidic conditions. The tagged peptides/proteins exhibited high water solubility thanks to the introduction of redundant oligo-Lys/Arg. In the final reaction, the tag can be quickly and cleanly detached by a standard deprotection reaction with trifluoroacetic acid. Herein, the development and application of these methods are described.